count where they don't have the same ID

i need to count all records in my table, but in the mp_id column there are repetitions

how to count only once where the content of mp_id is repeated?

so that the count is not wrong, i want the mp_id to count only once and not 3 or 4.

  $ingresos = Ingresosmp::All()->count('mp_id');

via Chebli Mohamed